JDOM XML parser example to modify an existing XML file :

  1. Add a new element
  2. Update existing element attribute
  3. Update existing element value
  4. Delete existing element

1. XML File

See before and after XML file.

File : file.xml – Original XML file.

<?xml version="1.0" encoding="UTF-8"?>
<company>
  <staff id="1">
    <firstname>yong</firstname>
    <lastname>mook kim</lastname>
    <nickname>mkyong</nickname>
    <salary>5000</salary>
  </staff>
</company>

Later, update above XML file via JDOM XML Parser.

  1. Add a new “age” element under staff
  2. Update the staff attribute id = 2
  3. Update salary value to 7000
  4. Delete “firstname” element under staff

File : file.xml – Newly modified XML file.

<?xml version="1.0" encoding="UTF-8"?>
<company>
  <staff id="2">
    <lastname>mook kim</lastname>
    <nickname>mkyong</nickname>
    <salary>7000</salary>
    <age>28</age>
  </staff>
</company>

2. JDOM Example

JDOM parser to update or modify an existing XML file.

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;
 
public class ModifyXMLFile {
	public static void main(String[] args) {
 
	  try {
 
		SAXBuilder builder = new SAXBuilder();
		File xmlFile = new File("c:\\file.xml");
 
		Document doc = (Document) builder.build(xmlFile);
		Element rootNode = doc.getRootElement();
 
		// update staff id attribute
		Element staff = rootNode.getChild("staff");
		staff.getAttribute("id").setValue("2");
 
		// add new age element
		Element age = new Element("age").setText("28");
		staff.addContent(age);
 
		// update salary value
		staff.getChild("salary").setText("7000");
 
		// remove firstname element
		staff.removeChild("firstname");
 
		XMLOutputter xmlOutput = new XMLOutputter();
 
		// display nice nice
		xmlOutput.setFormat(Format.getPrettyFormat());
		xmlOutput.output(doc, new FileWriter("c:\\file.xml"));
 
		// xmlOutput.output(doc, System.out);
 
		System.out.println("File updated!");
	  } catch (IOException io) {
		io.printStackTrace();
	  } catch (JDOMException e) {
		e.printStackTrace();
	  }
	}
}
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